1. Field of the Invention
The present invention relates to mobile pivot irrigation systems and particularly to an auto dry track directional spray device which has directional spray heads on each side of each support tower in a center-pivot sprinkler over the wheels so when the pivot irrigation system changes direction, the auto dry track directional spray device switches the spray heads automatically to be used over the wheels so the wheels are always traveling over dry soil with the water sprayed behind the wheels; alternately the auto dry track directional spray device may be used with a linear mobile irrigation system.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Irrigation systems comprising center-pivot sprinklers and linear movement sprinklers generally have one or more large main pipes or beams supported by one or more support towers with a series of spaced 360 degree spray heads along the length of the main pipes, including over the wheels. These sprinkler systems use large wheels to enable movement through an irrigated field. Each tower generally has two tires, one trailing the other. Due to the weight of the overhead sprinkler system and the softness of the wet ground caused by the 360 degree sprayers, the wheel tracks can become deep ruts, occasionally causing the sprinkler system to get stuck, and causing difficulty in harvesting crops.
In linear systems it is necessary to provide two directions of travel to go back and forth over the field. In center-pivot irrigation systems, it is also desirable to provide irrigation systems with two directions of travel required due to terrain or obstacles in the field.
While the prior art has made some provisions for not spraying in front of the wheels, the prior art primarily shows systems with only one direction of travel or systems with two directions of travel which require manual switching upon changing direction.
U.S. Pat. No. 5,505,386, issued Apr. 9, 1996 to Stone, describes a replacement drop sprinkler assembly for connection to an irrigation conduit of a center pivot irrigation system adjacent a tower support of the system includes a fluid conduit having first and second ends, the first end for fluid communication with an irrigation conduit of a center pivot irrigation system. The replacement drop sprinkler assembly projects water forwards or rearwards of the irrigation tower wheels, depending on the direction the irrigation system is traveling, while preventing substantial amounts of water from accumulating on the wheel surfaces and assists in the prevention of deep wheel ruts caused by irrigation system wheels tracking through newly formed mud.
U.S. Pat. No. 3,669,355, issued Jun. 13, 1972 to Jurgens, shows an irrigation apparatus which is self-propelled generally transversely across the ground, and in which the sprinkling or water distribution operation takes place rearwardly of the water supply pipe whereby to prevent undue wetting of the ground in the area of the self-propelling wheels whereby to provide good traction of the apparatus in the self-propelling operation.
U.S. Pat. No. 6,116,527, issued Sep. 12, 2000 to Granger et al, is for a center-pivot irrigation rut prevention device for installation in a conventional center-pivot irrigation system commonly found in agriculture which prevents ruts caused by the movement of the wheels in the drive mechanism of the irrigation system by re-directing the flow of water from the front of the drive mechanism of the irrigation system to the rear of the system thus enabling the wheels of the drive mechanism to travel of dry soil instead of freshly irrigated soil in the field. The invention consists of water pipe, quick connect attachments, a reciprocating sprinkler head, support struts and connecting ports for the drop lines supplied by the center-pivot irrigation system nearest the drive mechanism of the irrigation system.
U.S. Pat. No. 6,343,749, issued Feb. 5, 2002 to Thom, discloses a mobile drip irrigation system which includes an existing mobile irrigation system with the sprinkler heads removed and drip lines connected to the locations of the removed sprinkler heads. Each drip line includes a drop line extending from the irrigation system supply pipe, generally vertically to a lower end spaced slightly above the ground. The mobile drip irrigation system eliminates water being sprayed in the tracks of the wheels of the mobile towers.
Two U.S. Pat. Nos. 5,421,514 issued Jun. 6, 1995 and 5,586,728 issued Dec. 24, 1996 to McKenry, provide a pre-plant soil treatment method and apparatus. In FIG. 5, McKenry shows short dripper hoses of sufficient length which are attached to small manifolds and pulled behind the wheels in order to drench the area close to the wheel structures themselves. This prevents the wheels from being bogged down by soggy soil from the sprinklers. Minor adjustments in the attachment of the hoses may be made to allow this embodiment to be used in wheel line irrigation systems as well. McKenry also mentions a portable apparatus for pre-planting soil treatment consisting of a series of downwardly-pointing sprinklers which may be attached or added behind an existing center-pivot irrigation system or added behind an existing linear irrigation system.
U.S. Pat. No. 3,448,927, issued Jun. 10, 1969 to Blair, claims an irrigation spray line having central pipe flanked by two side pipes. Spray outlets are arranged so that such outlets are normally on the trailing side.
In irrigation systems which travel in two directions, both center-pivot and linear systems, what is needed is a two-sided directional sprinkler system in each tower which automatically switches sprinklers when the irrigation system changes directions so that the water from the directional sprinklers always falls behind the wheels to allow the wheels to travel over dry soil and prevent ruts.